This invention concerns locks of relatively light duty, particularly for cabinets, drawers, file cabinets, access panels and similar situations, typically used on office furniture but not on entry doors or other high-security applications such as safes. More specifically the invention encompasses an electronic cam lock that in some embodiments fits a standard cam lock opening.
Metal and wood file cabinets, desk and cabinet drawers, locker doors, access panels and doors, mail boxes, dispensers and other secure situations often utilize relatively simple lock mechanisms known as cam locks. Such cam locks may or may not involve a camming action. In some cases they move other mechanisms that are engaged with the door or drawer of the cabinet or engaged with other mechanisms that are linked to the door and drawer of the cabinet or multiple doors or drawers of the cabinet. In one of the simplest forms, a cam lock on a cabinet door typically fits in a ¾ inch diameter D-shaped or double D-shaped hole and, at the back side of the cam lock cylinder unit, has a metal blade or arm called a cam that rotates when the key is turned, from a position disengaged from surrounding cabinet hardware to a position of engagement in a slot or behind a ledge of the surrounding cabinet hardware. Other locks, such as those for desk drawers, commonly referred to as cabinet locks, involve a camming type action as the key and plug are rotated. The rotation causes a cam or nipple to move a deadbolt linearly to a locking or unlocking position or in the case of a spring loaded latch or deadlatch the rotation causes the cam or nipple to move a latch or deadlatch to unlocking position and removing the key keeps the latch or deadlatch in the extended locked position.
Metal filing cabinets often utilize cam locks, or a variation known as a plunger type lock in which a spring loaded plunger/lock cylinder located in the top horizontal margin of the cabinet, when pushed in, will lock all drawers. The use of a key releases the spring plunger to return to the outward position and unlock the drawers.
Locker and cabinet locks have included electronic locking devices, some of which utilized keypads and some of which utilized IButtons or other ID or non-volatile memory devices which work on contact to release the lock. See, for example, U.S. Pat. Nos. 5,894,277, 5,886,644, 6,655,180 and 6,791,450. The disclosures of all of these patents are incorporated herein by reference.
There is a need for a relatively simple, easily used, reliable and compact electronic lock, preferably a keypad lock but optionally operable by an electronic key, or both, for situations in which typically cam, plunger and cabinet locks were employed, and capable of fitting in a standard opening or bore of a standard cam, plunger or cabinet lock cylinder in a cabinet, door, access panel, mail box, dispenser, etc. and alternatively capable of fitting in a standard shell of a standard cam, plunger or cabinet lock cylinder in a cabinet, door, access panel, mail box, dispenser, etc. This is an objective of the current invention described below.
This invention is an improvement on the locks of U.S. Pat. Nos. 8,490,443 and 8,495,898, both owned by the assignee of the invention, and an improvement over U.S. Pat. No. 8,671,723. The disclosures of all of these patents are incorporated by reference in their entirety.